Apparatus and methods for radio frequency signal boosters

ABSTRACT

Provided herein are apparatus and methods for radio frequency (RF) signal boosters. In certain implementations, a multi-band signal booster is provided for boosting the uplink and downlink channels of at least a first frequency band and a second frequency band. In certain configurations, the downlink channels of the first and second channels are adjacent, and the signal booster includes a first amplification path for boosting the uplink channel of the first frequency band, a second amplification path for boosting the uplink channel of the second frequency band, and a third amplification path for boosting both downlink channels of the first and second frequency bands.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/173,375, filed Jun. 3, 2016, titled “APPARATUS AND METHODS FOR RADIOFREQUENCY SIGNAL BOOSTERS” which is a continuation of U.S. patentapplication Ser. No. 14/996,681, filed Jan. 15, 2016, titled “APPARATUSAND METHODS FOR RADIO FREQUENCY SIGNAL BOOSTERS,” which is acontinuation of U.S. patent application Ser. No. 14/811,650, filed Jul.28, 2015, titled “APPARATUS AND METHODS FOR RADIO FREQUENCY SIGNALBOOSTERS,” which is a continuation of U.S. patent application Ser. No.14/493,260, filed Sep. 22, 2014, titled “APPARATUS AND METHODS FOR RADIOFREQUENCY SIGNAL BOOSTERS,” now U.S. Pat. No. 9,100,839, issued Aug. 4,2015, which is a continuation of U.S. patent application Ser. No.13/872,877, filed Apr. 29, 2013, titled “APPARATUS AND METHODS FOR RADIOFREQUENCY SIGNAL BOOSTERS,” now U.S. Pat. No. 8,867,572, issued Oct. 21,2014, each of which are herein incorporated by reference in theirentireties.

BACKGROUND Field

Embodiments of the invention relate to electronic systems and, inparticular, to radio frequency (RF) signal boosters.

Description of the Related Technology

A cellular or mobile network can include base stations for communicatingwith wireless devices located within the network's cells. For example,the base stations can transmit signals to wireless devices via adownlink channel and can receive signals from the wireless devices viaan uplink channel. In the case of a network operating using frequencydivision duplexing (FDD), the downlink and uplink channels are separatein the frequency domain such that the frequency band operates using apair of frequency channels.

A wireless device may be unable to communicate with any of the basestations when located in a portion of the mobile network having poor orweak signal strength. For example, the wireless device may be unable tocommunicate with a particular base station when the wireless device andthe base station are separated by a large distance. Additionally,structures such as buildings or mountains can interfere with thetransmission and/or reception of signals sent between the wirelessdevice and a base station.

To improve the network's signal strength and/or the network's coverage,a radio frequency (RF) signal booster or repeater can be used to amplifysignals in the network. For example, the signal booster can be used toamplify or boost signals having frequencies associated with thefrequency ranges of the network's uplink and downlink channels. Incertain configurations, a signal booster can be used to provide networkcoverage inside of a structure, such as a home or building. However,other configurations are possible, such as implementations in which thesignal booster is used to provide coverage to remote network areas or inwhich the signal booster is coupled to a vehicle such as an automobile,bus, or train and used to boost network signals as the vehicle'sposition changes over time.

SUMMARY

In one embodiment, a radio frequency signal booster includes a firstamplification path, a second amplification path, and a thirdamplification path. The first amplification path includes a firstband-pass filter configured to pass a first channel of a first frequencyband and to attenuate a second channel of the first frequency band. Thefirst channel has a first channel type and the second channel has asecond channel type. Additionally, the first channel type comprises oneof an uplink channel or a downlink channel, and the second channel typecomprises the other of the uplink channel and the downlink channel. Thesecond amplification path includes a second band-pass filter configuredto pass a first channel of a second frequency band and to attenuate asecond channel of the second frequency band. The first channel of thesecond frequency band has the first channel type, and the second channelof the second frequency band has the second channel type. The thirdamplification path includes a third band-pass filter configured to passboth the second channel of the first frequency band and the secondchannel of the second frequency band. The third band-pass filter isfurther configured to attenuate both the first channel of the firstfrequency band and the first channel of the second frequency band.

In another embodiment, a multiplexer includes an antenna terminal, afirst terminal, a second terminal, a third terminal, a first band-passfilter, a second band-pass filter, and a third band-pass filter. Thefirst band-pass filter is electrically connected between the firstterminal and the antenna terminal. Additionally, the first band-passfilter is configured to pass a first channel of a first frequency bandand to attenuate a second channel of the first frequency band. The firstchannel has a first channel type and the second channel has a secondchannel type. The first channel type comprises one of an uplink channelor a downlink channel, and the second channel type comprises the otherof the uplink channel and the downlink channel. The second band-passfilter is electrically connected between the second terminal and theantenna terminal. The second band-pass filter is configured to pass afirst channel of a second frequency band and to attenuate a secondchannel of the second frequency band. The first channel of the secondfrequency band has the first channel type, and the second channel of thesecond frequency band has the second channel type. The third band-passfilter is electrically connected between the third terminal and theantenna terminal. The third band-pass filter is configured to pass boththe second channel of the first frequency band and the second channel ofthe second frequency band. The third band-pass filter is furtherconfigured to attenuate both the first channel of the first frequencyband and the first channel of the second frequency band.

In another embodiment, a method of radio frequency signal boosting isprovided. The method includes passing a first channel of a firstfrequency band using a first band-pass filter and attenuating a secondchannel of the first frequency band using the first band-pass filter.The first channel has a first channel type and the second channel has asecond channel type. The first channel type comprises one of an uplinkchannel or a downlink channel, and the second channel type comprises theother of the uplink channel and the downlink channel. The method furtherincludes passing a first channel of a second frequency band using asecond band-pass filter, and attenuating a second channel of the secondfrequency band using the second band-pass filter. The first channel ofthe second frequency band has the first channel type, and the secondchannel of the second frequency band has the second channel type. Themethod further includes passing both the second channel of the firstfrequency band and the second channel of the second frequency band usinga third band-pass filter, and attenuating both the first channel of thefirst frequency band and the first channel of the second frequency bandusing the third band-pass filter.

In another embodiment, a radio frequency signal booster includes ahousing, a first printed circuit board (PCB) positioned within a firstcavity of the housing, a second PCB positioned within a second cavity ofthe housing, and a shielding structure positioned between the first PCBand the second PCB. The first PCB includes a first plurality ofamplification paths configured to boost a first plurality of radiofrequency bands, and the first plurality of radio frequency bands eachhave a frequency less than about 1 GHz. The second PCB includes a secondplurality of amplification paths configured to boost a second pluralityof radio frequency bands, and the second plurality of radio frequencybands each have a frequency greater than about 1 GHz.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic block diagram of one example of a mobile network.

FIG. 2A is a schematic diagram of one example of a portion of afrequency spectrum.

FIG. 2B is schematic diagram of the frequency spectrum of FIG. 2A withannotations showing frequency locations of band-pass filter passbandsaccording to one embodiment.

FIG. 3 is a schematic diagram of a signal booster for uplink anddownlink channels for two bands according to one embodiment.

FIG. 4 is a schematic diagram of a signal booster for uplink anddownlink channels for five bands according to another embodiment.

FIG. 5A is a schematic diagram of a multiplexer according to oneembodiment.

FIG. 5B is a schematic diagram of a multiplexer according to anotherembodiment.

FIG. 6A is a perspective view of a signal booster in accordance with oneembodiment.

FIG. 6B is a top plan view of the signal booster of FIG. 6A with a topcover removed and with a first metal layer removed.

FIG. 6C is a bottom plan view of the signal booster of FIG. 6A with abottom cover removed and with a portion of a second metal layer removed.

FIG. 6D is a cross-section of the signal booster of FIGS. 6A-6C takenalong the lines 6D-6D.

DETAILED DESCRIPTION OF EMBODIMENTS

The following detailed description of certain embodiments presentsvarious descriptions of specific embodiments of the invention. However,the invention can be embodied in a multitude of different ways asdefined and covered by the claims. In this description, reference ismade to the drawings where like reference numerals may indicateidentical or functionally similar elements.

FIG. 1 is a schematic block diagram of one example of a mobile network10. The mobile network 10 includes a base station 1, a signal booster 2,a plurality of mobile devices 3 a-3 c (three shown), and a networkdevice 4.

The signal booster 2 is electrically coupled to a first antenna 5 a andto a second antenna 5 b. The signal booster 2 can retransmit signals toand receive signals from the base station 1 using the first antenna 5 a,and can retransmit signals to and receive signals from the plurality ofmobile devices 3 a-3 c and/or the network device 4 using the secondantenna 5 b. For example, the signal booster 2 can retransmit signals tothe base station 1 over one or more uplink channels, and can receivesignals from the base station 1 over one or more downlink channels.Additionally, the signal booster 2 can retransmit signals to theplurality of mobiles devices 3 a-3 c and/or the network device 4 overone or more downlink channels, and can receive signals from the devicesover one or more uplink channels. In one embodiment, the first antenna 5a is an outdoor antenna positioned external to a structure such as ahome or building and the second antenna 5 a is an indoor antennapositioned within the structure. However, other configurations arepossible. In the illustrated configuration, the first and secondantennas 5 a, 5 b can be external to the signal booster 2, and can beconnected, using, for example, cables. However, other configurations arepossible, including, for example, configurations in which the antennasare integrated as part of a signal booster. While illustrated with acommon housing for boosting all frequency bands of interest, theteachings herein are applicable to configurations in which the signalbooster 2 is implemented in multiples boxes or housings that communicatewith one another, such as over a wireless communication channel atdifferent frequency than the frequency bands the signal booster 2boosts.

Although FIG. 1 illustrates the signal booster 2 as communicating withone base station, the signal booster 2 typically communicates withmultiple base stations. For example, the signal booster 2 can be used tocommunicate with base stations associated with different cells of anetwork. Furthermore, in certain implementations, the signal booster 2can communicate with base stations associated with different networks,including, for example, networks associated with different wirelesscarriers and/or networks associated with different RF frequencies orbands.

For example, the mobile devices 3 a-3 c and/or the network device 4 cancommunicate at least in part over multiple frequency bands, including,for example, Universal Mobile Telecommunications System (UMTS) Band II,Band IV, Band V, Band XII, and/or Band XIII For instance, in oneexample, the first mobile device 3 a can operate using Advanced WirelessServices (AWS) (Band IV), the second mobile device 3 b can operate usingPersonal Communication Services (PCS) (Band II), and the third mobiledevice 3 c can operate using Cellular (CLR) services (Band V).Furthermore, in certain configurations, all or a subset of the mobiledevices 3 a-3 c and/or the network device 4 can communicate using LongTerm Evolution (LTE), and may transmit and receive Band XII signals,Band XIII signals, and/or signals associated with other LTE bands.Although specific examples of frequency bands and communicationtechnologies have been described above, the teachings herein areapplicable to a wide range of frequency bands and communicationsstandards.

Accordingly, the signal booster 2 can be configured to boost signalsassociated with multiple frequency bands so as to improve networkreception for each of the mobile devices 3 a-3 c and the network device4. Configuring the signal booster 2 to service multiple frequency bandscan improve network signal strength for multiple devices. For example,the signal booster 2 can improve network signal strength of devicesusing the same or different frequency bands, the same or differentwireless carriers, and/or the same or different wireless technologies.Configuring the signal booster 2 as a multi-band repeater can avoid thecost of separate signal boosters for each specific frequency band and/orwireless carrier. Additionally, configuring the signal booster 2 as amulti-band repeater can also ease installation, reduce cabling, and/orissues associated with combining multiple repeaters.

The plurality of mobile devices 3 a-3 c can represent a wide range ofmobile or portable communication devices, including, for example,multi-band mobile phones. The network device 4 can represent a widerange of other devices configured to communicate over one or more mobilenetworks, including, for example, computers, televisions, modems,routers, or other electronics. In one embodiment, the network device 4is another signal booster. Although FIG. 1 illustrates the signalbooster 2 as communicating with three mobile devices 3 a-3 c and onenetwork device 4, the signal booster 2 can be used to communicate withmore or fewer mobile devices and/or more or fewer network devices.

FIG. 2A is a schematic diagram of one example of a portion of afrequency spectrum 20. The frequency spectrum 20 includes a Band XIIuplink channel, a Band XII downlink channel, a Band XIII downlinkchannel, a Band XIII uplink channel, a Band V uplink channel, a Band Vdownlink channel, a Band IV uplink channel, a Band II uplink channel, aBand II downlink channel, and a Band IV downlink channel. The frequencyspectrum 20 of FIG. 2A illustrates one example of the frequency bandsthat a signal booster described herein can be used to boost. However,other configurations are possible, such as implementations in which thesignal booster amplifies more or fewer frequency bands and/or adifferent combination of frequency bands.

In certain implementations, the Band XII uplink channel can have afrequency range of about 698 MHz to about 716 MHz, and the Band XIIdownlink channel can have a frequency range of about 728 MHz to about746 MHz. Additionally, in certain implementations the Band XIII uplinkchannel can have a frequency range of about 776 MHz to about 787 MHz,and the Band XIII downlink channel can have a frequency range of about746 MHz to about 757 MHz. Furthermore, in certain implementations theBand V uplink channel can have a frequency range of about 824 MHz toabout 849 MHz, and the Band V downlink channel can have a frequencyrange of about 869 MHz to about 894 MHz. Additionally, in certainimplementations the Band IV uplink channel can have a frequency range ofabout 1710 MHz to about 1755 MHz, and the Band IV downlink channel canhave a frequency range of about 2110 MHz to about 2155 MHz. Furthermore,in certain implementations the Band II uplink channel can have afrequency range of about 1850 MHz to about 1910 MHz, and the Band IIdownlink channel can have a frequency range of about 1930 MHz to about1990 MHz.

Although specific frequency ranges have been provided above, persons ofordinary skill in the art will appreciate that the frequencies of thebands can vary by geographical region and/or can change over time basedon regulations set by governing agencies such as the FederalCommunications Commission (FCC) or the Canadian Radio-television andTelecommunications Commission (CRTC). Additionally, the teachings hereinare applicable to configurations in which a signal booster providesamplification to a portion of the sub-bands associated with one or morefrequency bands. For example, certain frequency bands, including, forexample, the PCS band, can be associated with a plurality of sub-bands,and the teachings herein are applicable to configurations in which thesignal booster operates to provide boosting for only some of thesub-bands.

Certain signal boosters can use a separate amplification path for eachchannel of each frequency band that the signal booster is used to boostor repeat. For example, each amplification path of the signal boostercan include a band-pass filter having a passband for passing aparticular uplink or downlink channel while attenuating or blockingother frequencies. Configuring the signal booster in this manner can aidin maintaining the booster's compliance with communication standardsand/or regulator rules, such as those limiting spurious and/orout-of-band emissions.

The radio frequency spectrum has become increasingly crowded withsignals as mobile technologies have advanced and the demand for highspeed wireless communication has expanded. For example, there has beenan increase in a number and proximity of frequency bands that are beingutilized by mobile devices and networks.

The increased crowding of the radio frequency spectrum has constrainedthe design and development of signal boosters, particular multi-bandsignal boosters that provide boosting across multiple frequency bands,including, for example, adjacent frequency bands. For example, aband-pass filter used to select a particular uplink or downlink channelfor boosting can have a non-ideal passband associated with roll-off nearthe passband's edges. The filter's roll-off can lead to an increase inundesired spurious and/or out-of-band emissions associated withamplification of signals outside of the particular channel's frequencyband. Although a particular uplink or downlink channel may be selectedby using a relatively sharp filter such as a cavity filter, such filterscan be prohibitive in cost and/or size.

Provided herein are apparatus and methods for RF signal boosters. Incertain implementations, a multi-band signal booster is provided forboosting the uplink and downlink channels of at least a first frequencyband and a second frequency band. The first and second frequency bandscan be closely positioned in frequency, and the first and secondfrequency bands can include uplink or downlink channels that areadjacent. For example, the duplex of the first and second frequencybands can be reversed such that the order in frequency of the firstfrequency band's uplink and downlink channels is flipped or reversedrelative to the second frequency band's uplink and downlink channels.However, other configurations are possible, such as when two frequencybands have that are disjoint, and the uplink and/or downlink channels ofthe bands are adjacent.

In certain configurations, the downlink channels of the first and secondchannels are adjacent, and the signal booster includes a firstamplification path for boosting the uplink channel of the firstfrequency band, a second amplification path for boosting the uplinkchannel of the second frequency band, and a third amplification path forboosting the downlink channels of the first and second frequency bands.For example, the first amplification path can include a first band-passfilter for passing the first frequency band's uplink channel and forattenuating other frequencies such as the first frequency band'sdownlink channel, and the second amplification path can include a secondband-pass filter for passing the second frequency band's uplink channeland for attenuating other frequencies such as the second frequencyband's downlink channel. Additionally, the third amplification path caninclude a third band-pass filter for passing the downlink channels ofthe first and second frequency bands and for attenuating otherfrequencies such as the uplink channels of the first and secondfrequency bands. Thus, the signal booster can include a sharedamplification path that operates to boost or repeat the downlinkchannels of adjacent frequency bands.

However, in other configurations, the uplink channels of the first andsecond channels are adjacent, and the signal booster includes a firstamplification path for boosting the downlink channel of the firstfrequency band, a second amplification path for boosting the downlinkchannel of the second frequency band, and a third amplification path forboosting the uplink channels of the first and second frequency bands.

The signal boosters described herein can be used to boost multiplefrequency bands, thereby improving signal strength for devices usingdifferent communications technologies and/or wireless carriers.Configuring the signal booster in this manner can avoid the cost ofmultiple signal boosters, such as having a specific signal booster foreach frequency band. Additionally, the signal boosters can have reducedcomponent count and/or size, since band-pass filters, amplifiers,attenuators and/or other circuitry can be shared for at least twochannels. Furthermore, the signal boosters herein can be implementedwithout the cost of filters with relatively sharp passbands, such ascavity filters, which can have a high cost and/or a large area. Thus,the signal boosters herein can be implemented using filters having arelatively low cost and/or a relatively small size, such as surfaceacoustic wave (SAW) filters and/or ceramic filters.

FIG. 2B is schematic diagram of the frequency spectrum of FIG. 2A withannotations showing frequency locations of band-pass filter passbandsaccording to one embodiment.

In the illustrated configuration, a first band-pass filter passband 31has been implemented to pass or select a Band XII uplink channel, and asecond band-pass filter passband 32 has been implemented to pass a BandXIII uplink channel. Furthermore, a third band-pass filter passband 33has been implemented to pass both a Band XII downlink channel and a BandXIII downlink channel. Additionally, a fourth band-pass filter passband34 has been implemented to pass a Band V uplink channel, and a fifthband-pass filter passband 35 has been implemented to pass a Band Vdownlink channel. Furthermore, a sixth band-pass filter passband 36 hasbeen implemented to pass a Band IV uplink channel, and a seventhband-pass filter passband 37 has been implemented to pass a Band IIuplink channel. Additionally, an eighth band-pass filter passband 38 hasbeen implemented to pass a Band II downlink channel, and a ninthband-pass filter passband 39 has been implemented to pass a Band IVdownlink channel. Although FIG. 2B illustrates a single passband foreach frequency channel, a signal booster can include a plurality ofband-pass filters that are cascaded, with or without interveningcircuitry, to achieve an overall channel filtering.

As used herein, a band-pass filter can “pass” a particular frequencychannel when the frequency channel is substantially within the band-passfilter's passband, even when the passband provides gain or loss in thepassband. Accordingly, the teachings herein are not limited to band-passfilters having unity-gain passbands. Furthermore, in certainimplementations, a band-pass filter herein can be implemented bycascading a low-pass filter and a high-pass filter. For example,cascading a high-pass filter having a cutoff frequency of f₁ and alow-pass filter having a cutoff frequency of f₂, where f₂ is greaterthan f₁, can operate to provide a band-pass filter having a passbandbetween about f₁ and about f₂.

As shown in FIG. 2B, the third band-pass filter passband 33advantageously passes the downlink channels of both Band XII and BandXIII, which are adjacent frequency bands. The illustrated configurationtakes advantage of the reverse duplex of the Band XIII frequency bandrelative to that of the Band XII frequency band. For example, a typicalfrequency band such as Band XIII, Band II, Band IV, and Band V uses anuplink channel that is at a lower frequency than a correspondingdownlink channel of the same band. However, Band XIII uses a reverseconfiguration in which the downlink channel is at a lower frequencyrelative to the uplink channel. Configuring a signal booster to have aband-pass filter that passes both the Band XII and Band XIII downlinksignals can avoid a need for sharp band-pass filters for separatelyfiltering the downlink bands, which can be difficult using relativesmall and/or low-cost filters such as SAW filters and/or ceramicfilters, which can have a non-ideal passband and can provideinsufficient channel filtering or selectivity.

FIG. 3 is a schematic diagram of a signal booster 50 for uplink anddownlink channels for two bands according to one embodiment. The signalbooster 50 includes first and second multiplexers 55 a, 55 b, first tothird amplification paths or circuits 51-53, and a control circuit 54.In the illustrated configuration, the signal booster 50 is electricallycoupled to the first and second antennas 5 a, 5 b, such as by cables orwires. However, other configurations are possible, including, forexample, configurations in which the antennas are integrated with asignal booster.

The first multiplexer 55 a includes a first terminal electricallyconnected to an output of the first amplification path 51, a secondterminal electrically connected to an output of the second amplificationpath 52, a third terminal electrically connected to an input of thethird amplification path 53, and an antenna terminal electricallyconnected to the first antenna 5 a. The second multiplexer 55 b includesa first terminal electrically connected to an input of the firstamplification path 51, a second terminal electrically connected to aninput of the second amplification path 52, a third terminal electricallyconnected to an output of the third amplification path 53, and anantenna terminal electrically connected to the second antenna 5 b.

The first amplification path 51 includes a first low noise amplifier(LNA) 61 a, a first band-pass filter 62 a, a first attenuator 63 a, anda first power amplifier (PA) 64 a. The first LNA 61 a, the firstband-pass filter 62 a, the first attenuator 63 a, and the first PA 64 aare cascaded with an input of the first LNA 61 a operating as the firstamplification path's input and with an output of the first PA 64 aoperating as the first amplification path's output. The secondamplification path 52 includes a second LNA 61 b, a second band-passfilter 62 b, a second attenuator 63 b, and a second PA 64 b. The secondLNA 61 b, the second band-pass filter 62 b, the second attenuator 63 b,and the second PA 64 b are cascaded with an input of the second LNA 61 boperating as the second amplification path's input and with an output ofthe second PA 64 b operating as the second amplification path's output.The third amplification path 53 includes a third LNA 61 c, a thirdband-pass filter 62 c, a third attenuator 63 c, and a third PA 64 c. Thethird LNA 61 c, the third band-pass filter 62 c, the third attenuator 63c, and the third PA 64 c are cascaded with an input of the third LNA 61c operating as the third amplification path's input and with an outputof the third PA 64 c operating as the third amplification path's output.

In one embodiment, the gain of each of the first to third amplificationpaths 51-53 is selected to be in the range of about 10 dB to about 90dB. In certain configurations, the gain of one or more of the first tothird amplification paths 51-53 can be externally controlled, such as byusing one or more switches and/or by using digital configuration.Although one example of gain values has been provided, otherconfigurations are possible.

The first to third LNAs 61 a-61 c can provide low noise amplificationfor the first to third amplification paths 51-53, respectively. Incertain implementations, the first to third LNAs 61 a-61 c can be usedto amplify signals having a relatively small amplitude while adding orintroducing a relatively small amount of noise. For example, in oneembodiment, each of the LNAs 61 a-61 c has a noise figure of 1 dB orless. However, other configurations are possible.

The first to third band-pass filters 62 a-62 c include inputselectrically coupled to outputs of the first to third LNAs 61 a-61 c,respectively. The first to third band-pass filters 62 a-62 c can filterthe frequency content of the amplified signals generated by the first tothird LNAs 61 a-61 c, respectively. In certain embodiments, the first tothird band-pass filters 62 a-62 c can be analog filters with fixedfiltering characteristics and/or low costs, such as ceramic or SAWfilters. However, other configurations are possible. Additional detailsof the first to third band-pass filters 62 a-62 c will be describedfurther below.

The first to third attenuators 63 a-63 c can be used to attenuate thefiltered signals generated by the first to third band-pass filters 62a-62 c, respectively. The first to third attenuators 63 a-63 c can beused to limit a gain of the first to third amplification paths 51-53,respectively. For example, it can be desirable to provide attenuation inone or more of the first to third amplification paths 51-53, such as inconfigurations in which one or more of the input signals to theamplification paths has a relatively large amplitude, which can occurwhen the signal booster 50 is positioned relatively close to a basestation. In one embodiment, the attenuation of the first to thirdattenuators 63 a-63 c can be controlled using one or more processing orcontrol units. For example, one or more embedded CPUs can be used toprovide gain control, such as programmable gain control. In certainimplementations, the first to third attenuators 63 a-63 c can beimplemented using analog attenuation components. However, otherconfigurations are possible, such as implementations using digitalattenuators, such as digital step attenuators.

The first to third PAs 64 a-64 c can be used to amplify the attenuatedsignals generated by the first to third attenuators 63 a-63 c,respectively. The first to third PAs 64 a-64 c can be used to generateamplified RF output signals that have a magnitude suitable fortransmission via an antenna. The first to third PAs 64 a-64 c can beimplemented using single or multi-stage configurations, including, forexample, multi-stage configurations using automatic gain control (AGC).

The control circuit 54 can be used to control the operation of thecircuitry of the signal booster 50. For example, in certainimplementations, the control circuit 54 can be used to control the levelof attenuation of the first to third attenuators 63 a-63 c, an amount ofgain of the first to third PAs 64 a-64 c and/or the first to third LNAs61 a-61 c, and/or to provide other control operations in signal booster50. For clarity of the figures, connections and control signalsgenerated by the control circuit 54 have been omitted. Additionally,although not illustrated in FIG. 3, the signal booster 50 can includeadditional circuitry such as directional couplers, which can aid thecontrol circuit 54 in controlling output power levels of the first tothird amplification paths 51-53. Accordingly, in certain implementationsthe control circuit 54 can operate to provide automatic gain control(AGC). The control circuit 54 can also operate to provide otherfunctionality, including, for example, automatic oscillation detectionand/or automatic shutdown to prevent interference with base stations.

The first and second multiplexers 55 a, 55 b can be used to providemultiplexing between the first to third amplification paths 51-53 andthe first and second antennas 5 a, 5 b, respectively. For example, thefirst multiplexer 55 a can be used to combine the amplified outputsignals from the first and second amplification paths 51, 52 fortransmission via the first antenna 5 a, and to filter a receive signalreceived on the first antenna 5 a to provide an input signal to thethird amplification path 53. Additionally, the second multiplexer 55 bcan be used to provide the amplified output signal from the thirdamplification path 53 to the second antenna 5 b, and to filter a receivesignal received on the second antenna 5 b to provide appropriate inputsignals to the first and second amplification paths 51, 52.

In certain implementations, the first multiplexer 55 a can include aband-pass filter associated with each of the multiplexer's first tothird terminals. Additionally, the second multiplexer 55 b can include aband-pass filter associated with each of the multiplexer's first tothird terminals. The band-pass filter associated with a particularterminal can be configured to pass frequencies corresponding to those ofan associated amplification path that is connected to the terminal. Forexample, in certain configurations, the band-pass filters of themultiplexers 55 a, 55 b have a passband similar to that of acorresponding one of the band-pass filters 62 a-62 c of theamplification paths 51-53. One example of a suitable implementation ofthe first and second multiplexers 55 a, 55 b can be similar to thatdescribed below with respect to FIG. 5A.

Furthermore, in certain implementations, one or both of the first andsecond multiplexers 55 a, 55 b can be omitted. For example, in oneembodiment, the signal booster 50 omits the first and secondmultiplexers 55 a, 55 b in favor of using a separate antenna at theinput and output of each of the amplification paths 51-53.

The signal booster 50 can be used to boost the uplink and downlinkchannels of first and second frequency bands that are adjacent orclosely positioned in frequency, such as when adjacent frequency bandshave a duplex that is reversed. For example, in one embodiment, thesignal booster 50 is used to boost Band XII and Band XIII, which areadjacent in frequency and have uplink and downlink channels that areflipped or reversed in frequency such that the Band XII downlink channeland the Band XIII downlink channel are positioned between the Band XIIuplink channel and the Band XIII uplink channel. For example, the BandXII downlink channel can have a greater frequency than the Band XIIuplink channel, and the Band XIII uplink channel can have a greaterfrequency than the Band XIII downlink channel.

Additionally, the signal booster 50 includes the first and secondamplification paths 51, 52, which can be used to amplify the uplinkchannels of the first and second bands. Furthermore, the signal booster50 includes the third amplification path 53, which operates as a sharedamplification path that boosts both the downlink channel of the firstfrequency band and the downlink channel of the second frequency band.Thus, in contrast to a conventional signal booster that includes aseparate amplification path for each frequency channel that is boosted,the illustrated configuration includes a shared amplification path foramplifying adjacent downlink channels, such as close or abuttingdownlink channels.

To provide suitable channel filtering, the first band-pass filter 62 acan pass the first frequency band's uplink channel and attenuate thefirst frequency band's downlink channel. Additionally, second band-passfilter 62 b can pass the second frequency band's uplink channel andattenuate the second frequency band's downlink channel. Furthermore, thethird band-pass filter 62 c can pass the downlink channels of both thefirst and second frequency bands and attenuate the uplink channels ofboth the first and second frequency bands. Thus, the third amplificationpath 53 is shared between the downlink channels of the first and secondfrequency bands and operates to simultaneously boost or repeat thedownlink channels. Since the third amplification path 53 boosts thedownlink channels of both the first and second frequency bands,relatively sharp filters need not be used to separately filter thesechannels. Thus, the first to third band-pass filters 62 a-62 c can beimplemented using filters having a relatively low cost and/or arelatively small size, such as surface acoustic wave (SAW) and/orceramic filters.

Although the signal booster 50 has been described in the context of asingle amplification path boosting multiple downlink channels, theteachings herein are applicable to configurations in which a singleamplification path is used to boost multiple uplink channels. Forexample, the teachings herein are applicable to configurations in whicha shared amplification path is used to boost the uplink channels of twofrequency bands that are adjacent, such as when the duplex of the firstand second frequency bands is reversed such that the bands' uplinkchannels are positioned between the bands' downlink channels.

In one embodiment, the adjacent uplink channels or the adjacent downlinkchannels of the first and second frequency bands are separated infrequency by less than about 10 MHz. Furthermore, in certainimplementations, the adjacent uplink channels or the adjacent downlinkchannels of the first and second frequency bands are abutting, such thatthere is substantially no separation or gap (e.g., about 0 MHz) betweenthe channel frequencies.

Although one implementation of a signal booster is illustrated in FIG.3, other configurations are possible. For example, the signal boostercan include more or fewer amplifications paths. Additionally, one ormore of the amplification paths can be modified to include more or fewercomponents and/or a different arrangement of components. For example, incertain implementations, the order of a band-pass filter and anattenuator can be reversed in a cascade, the band-pass filters can bepositioned before the LNAs in one or more of the cascades, and/oradditional components can be inserted in the cascade.

FIG. 4 is a schematic diagram of a signal booster 100 for uplink anddownlink channels for five bands according to another embodiment. Thesignal booster 100 includes the control circuit 54, first to fourthmultiplexers 112 a-112 d, first and second diplexers 111 a, 111 b, andfirst to ninth amplification paths or circuits 101-109. The signalbooster 100 is electrically coupled to the first and second antennas 5a, 5 b.

The first diplexer 111 a includes an antenna terminal electricallyconnected to the first antenna 5 a, a first terminal electricallyconnected to an antenna terminal of the first multiplexer 112 a, and asecond terminal electrically connected to an antenna terminal of thethird multiplexer 112 c. The second diplexer 111 b includes an antennaterminal electrically connected to the second antenna 5 b, a firstterminal electrically connected to an antenna terminal of the secondmultiplexer 112 b, and a second terminal electrically connected to anantenna terminal of the fourth multiplexer 112 d.

The first multiplexer 112 a further includes a first terminalelectrically connected to an output of the first amplification path 101,a second terminal electrically connected to an output of the secondamplification path 102, a third terminal electrically connected to aninput of the third amplification path 103, a fourth terminalelectrically connected to an output of the fourth amplification path104, and a fifth terminal electrically connected to an input of thefifth amplification path 105. The second multiplexer 112 b furtherincludes a first terminal electrically connected to an input of thefirst amplification path 101, a second terminal electrically connectedto an input of the second amplification path 102, a third terminalelectrically connected to an output of the third amplification path 103,a fourth terminal electrically connected to an input of the fourthamplification path 104, and a fifth terminal electrically connected toan output of the fifth amplification path 105.

The third multiplexer 112 c includes a first terminal electricallyconnected to an input of the sixth amplification path 106, a secondterminal electrically connected to an output of the seventhamplification path 107, a third terminal electrically connected to aninput of the eighth amplification path 108, and a fourth terminalelectrically connected to an output of the ninth amplification path 109.The fourth multiplexer 112 d includes a first terminal electricallyconnected to an output of the sixth amplification path 106, a secondterminal electrically connected to an input of the seventh amplificationpath 107, a third terminal electrically connected to an output of theeighth amplification path 108, and a fourth terminal electricallyconnected to an input of the ninth amplification path 109.

In the illustrated configuration, the first amplification path 101 canprovide boosting to a Band XII uplink channel, and the secondamplification path 102 can provide boosting to a Band XIII uplinkchannel. Furthermore, the third amplification path 103 can provideboosting to both the Band XII and Band XIII downlink channels.Additionally, the fourth amplification path 104 can provide boosting tothe Band V uplink channel, and the fifth amplification path 105 canprovide boosting to the Band V downlink channel. Furthermore, the sixthamplification path 106 can provide boosting to the Band IV downlinkchannel, and the seventh amplification path 107 can provide boosting tothe Band IV uplink channel. Additionally, the eighth amplification path108 can provide boosting to the Band II downlink channel, and the ninthamplification path 109 can provide boosting to the Band II uplinkchannel.

The first and second multiplexers 112 a, 112 b can provide multiplexingoperations for the first to fifth amplification paths 101-105. The firstand second multiplexers 112 a, 112 b can include a band-pass filter foreach of the multiplexers' first to fifth terminals. The band-passfilters can have passbands positioned at frequencies corresponding tothe uplink or downlink channels of an associated amplification path.Additionally, the third and fourth multiplexers 112 c, 112 d can providemultiplexing operations for the sixth to ninth amplification paths106-109. The third and fourth multiplexers 112 c, 112 d can include aband-pass filter for each of the multiplexers' first to fourthterminals. The band-pass filters can have passbands positioned atfrequencies corresponding to the uplink or downlink channels of anassociated amplification path.

The first diplexer 111 a can be used to combine/split signals from/tothe antenna terminals of the first and third multiplexers 112 a, 112 c,and can provide the combined signal to the first antenna 5 a.Additionally, the second diplexer 111 b can be used to combine/splitsignals on the antenna terminals of the second and fourth multiplexers112 b, 112 d, and can provide the combined signal to the second antenna5 b. Including the first and second diplexers 111 a, 111 b in the signalbooster 100 can aid the signal booster 100 in operating over disjointfrequency bands by combining signals separated by a relatively largefrequency difference. For example, in the illustrated configuration, thefirst and second diplexers 111 a, 111 b have been used in combinationwith the multiplexers 112 a-112 d to multiplex Band XII, Band XIII, andBand V signals with Band II and Band IV signals.

The first to ninth amplification paths 101-109 include differentcombinations of components, such as amplifiers, attenuators, andband-pass filters, selected to achieve an overall amplificationcharacteristic desirable for a particular band.

In the illustrated configuration, the first amplification path 101includes a cascade of an LNA 121 a, a first band-pass filter 122 a, apower level control block or circuit 123 a, a first intermediateamplifier or gain block 124 a, a second band-pass filter 125 a, anattenuator 126 a, a second gain block 127 a, a third band-pass filter128 a, a third gain block 129 a, a fourth band-pass filter 130 a, and apower amplifier 132 a. Additionally, the second amplification path 102includes a cascade of an LNA 121 b, a first band-pass filter 122 b, apower level control block 123 b, a first gain block 124 b, an attenuator126 b, a second band-pass filter 125 b, a second gain block 127 b, athird band-pass filter 128 b, a third gain block 129 b, a fourthband-pass filter 130 b, and a power amplifier 132 b. Furthermore, thethird amplification path 103 includes a cascade of an LNA 121 c, a powerlevel control block 123 c, a first band-pass filter 122 c, a first gainblock 124 c, an attenuator 126 c, a second gain block 127 c, a secondband-pass filter 125 c, a third gain block 129 c, a fourth gain block131 c, a third band-pass filter 128 c, and a power amplifier 132 c.Additionally, the fourth amplification path 104 includes a cascade of anLNA 121 d, a first band-pass filter 122 d, a power level control block123 d, a first gain block 124 d, a second band-pass filter 125 d, anattenuator 126 d, a second gain block 127 d, a third band-pass filter128 d, a third gain block 129 d, and a power amplifier 132 d.Furthermore, the fifth amplification path 105 includes a cascade of anLNA 121 e, a first band-pass filter 122 e, a power level control block123 e, a first gain block 124 e, a second band-pass filter 125 e, anattenuator 126 e, a second gain block 127 e, a third band-pass filter128 e, a third gain block 129 e, and a power amplifier 132 e.

Additionally, in the illustrated configuration, the sixth amplificationpath 106 includes a cascade of an LNA 121 f, a first band-pass filter122 f, a power level control block 123 f, a first gain block 124 f, asecond band-pass filter 125 f, an attenuator 126 f, a third band-passfilter 128 f, a second gain block 127 f, a fourth band-pass filter 130f, a third gain block 129 d, and a power amplifier 132 f. Furthermore,the seventh amplification path 107 includes a cascade of an LNA 121 g, afirst band-pass filter 122 g, a power level control block 123 g, a firstgain block 124 g, a second band-pass filter 125 g, an attenuator 126 g,a second gain block 127 g, a third band-pass filter 128 g, a third gainblock 129 g, a fourth band-pass filter 130 g, a fourth gain block 131 g,and a power amplifier 132 g. Additionally, the eighth amplification path108 includes a cascade of an LNA 121 h, a first band-pass filter 122 h,a power level control block 123 h, a first gain block 124 h, a secondband-pass filter 125 h, an attenuator 126 h, a third band-pass filter128 h, a second gain block 127 h, a fourth band-pass filter 130 h, athird gain block 129 h, and a power amplifier 132 h. Furthermore, theninth amplification path 109 includes a cascade of an LNA 121 i, a firstband-pass filter 122 i, a power level control block 123 i, a first gainblock 124 i, an attenuator 126 i, a second band-pass filter 125 i, asecond gain block 127 i, a third band-pass filter 128 i, a third gainblock 129 i, and a power amplifier 132 i.

The signal booster 100 of FIG. 4 is similar to the signal booster 50 ofFIG. 3, except that the signal booster 100 of FIG. 4 has been expandedto provide boosting to five frequency bands and has been adapted toinclude additional filters, amplifiers and other circuitry, such asadditional components in cascades associated with the amplificationpaths. In the illustrated configuration, each of the amplification paths101-109 includes an LNA, a power amplifier, an attenuator, and at leastone band-pass filter. Additionally, as shown in FIG. 4, the connectionbetween the amplifications paths 101-109 and the antennas 5 a, 5 bthrough the multiplexers 112 a-112 d and the diplexers 111 a, 111 b canbe symmetric. For example, in the illustrated configuration, each of theamplification paths 101-109 is coupled to the antennas 5 a, 5 b throughone multiplexer and one diplexer. Configuring the signal booster 100 inthis manner can provide balance between the amplification paths, whichcan reduce overall noise. Although configuring the signal booster 100 tobe symmetric can reduce noise, other implementations are possible,including, for example, asymmetric configurations.

As shown in FIG. 4, a type, number, and/or order of the components in anamplification path can be selected to provide a desired amplificationcharacteristic for a particular frequency channel. For example, a numberof gain blocks can be selected to achieve a desired amplificationcharacteristic depending upon the band and channel(s) being amplified,while a number of pass-band filters can be selected to achieve a desiredfiltering characteristic for the channel(s).

In certain configurations, the power level control blocks 123 a-123 iare included to adjust the gain of the first to ninth amplificationpaths 101-109, respectively. For example, in certain implementations,the power level control blocks 123 a-123 i can be used to adjust orlimit the gain when the gain of an associated amplification path exceedsa maximum power threshold level. However, in other configurations, oneor more of the power level control blocks 123 a-123 i can be omitted.

In the illustrated configuration, the signal booster 100 includes thethird amplification path 103, which has been configured to boost both aBand XII downlink channel and a Band XIII downlink channel. The thirdamplification path 103 includes first to third band-pass filters 122 c,125 c, 128 c, each of which can have a passband configured to pass boththe Band XII and Band XIII downlink channels while attenuating otherfrequency components. Thus, in contrast to the signal booster 50 of FIG.3 which includes one band-bass filter 62 b in the third amplificationpath 53, the signal booster 100 illustrates a configuration using threeband-pass filters 122 c, 125 c, 128 c in the third amplification path103. Using a plurality of band-pass filters in an amplification path canincrease a strength or degree of filtering. For example, cascadingmultiple band-pass filters can be useful in high gain configurations, inwhich an amplification path has a relatively large amount of gain.

Although FIG. 4 illustrates one example of a signal booster inaccordance with the teachings herein, other configurations are possible.For example, the teachings herein are applicable to configurations inwhich the signal booster 100 boosts more or fewer bands, or a differentcombination of bands.

FIG. 5A is a schematic diagram of a multiplexer 150 according to oneembodiment. The multiplexer 150 includes a first terminal 151, a secondterminal 152, a third terminal 153, an antenna terminal 156, a combiner159, a first band-pass filter 161, a second band-pass filter 162, and athird band-pass filter 163. The first band-pass filter 161 iselectrically connected between the first terminal 151 and the antennaterminal 156 through the combiner 159. Additionally, the secondband-pass filter 162 is electrically connected between the secondterminal 152 and the antenna terminal 156 through the combiner 159.Furthermore, the third band-pass filter 163 is electrically connectedbetween the third terminal 153 and the antenna terminal 156 through thecombiner 159. The combiner 159 can be used to enhance performance bycombining RF signals associated with the band-pass filters 161-163 whilehelping to control characteristic impedance so as to reduce or preventsignal reflections. However, in certain configurations, the combiner 159can be omitted.

Although FIG. 5A illustrates the multiplexer 150 as including certainterminals and components, the multiplexer 150 can be adapted to includeadditional structures, such as additional components cascaded with theband-pass filters 161-163 and/or additional terminals associated withother frequency channels. In certain embodiments, the first to thirdband-pass filters 161-163 can be analog filters with fixed filteringcharacteristics and/or low cost, such as ceramic or SAW filters.However, other configurations are possible.

In one embodiment, the multiplexer 150 is used in a signal booster thatboosts at least the uplink and downlink channels of first and secondfrequency bands, which have downlink channels that are adjacent, such aswhen the first and second frequency bands are duplex reversed such thatthe bands' downlink channels are positioned between the bands' uplinkchannels. Additionally, the first band-pass filter 161 can pass anuplink channel of the first frequency band and can attenuate thedownlink channel of the first frequency band. Furthermore, the secondband-pass filter 162 can pass an uplink channel of the second frequencyband and can attenuate the downlink channel of the second frequencyband. Furthermore, the third band-pass filter 163 can pass the downlinkchannels of both the first and second frequency bands and can attenuatethe uplink channels of both the first and second frequency bands.Additional details of the multiplexer 150 can be similar to thosedescribed earlier.

Although one embodiment of a multiplexer has been described, otherconfigurations are possible. For example, the teachings herein areapplicable to multiplexer configurations used in a signal booster thatboosts at least the uplink and downlink channels of first and secondfrequency bands, which are duplex reversed such that the bands' uplinkchannels are positioned between the bands' downlink channels. In such aconfiguration, the third band-pass filter 163 can pass the uplinkchannels of both the first and second frequency bands and can attenuatethe downlink channels of both the first and second frequency bands.

FIG. 5B is a schematic diagram of a multiplexer 170 according to oneembodiment. The multiplexer 170 includes a first terminal 151, a secondterminal 152, a third terminal 153, a fourth terminal 154, a fifthterminal 155, an antenna terminal 156, a combiner 159, a first band-passfilter 161, a second band-pass filter 162, a third band-pass filter 163,a fourth band-pass filter 164, and a fifth band-pass filter 165.

The multiplexer 170 of FIG. 5B is similar to the multiplexer 150 of FIG.5A, except that the multiplexer 170 further includes the fourth andfifth terminals 154, 155 and the fourth and fifth band-pass filters 164,165. In one embodiment, the fourth terminal 154 and the fifth terminal155 are configured to operate over an uplink channel of a thirdfrequency band and a downlink channel of the third frequency band,respectively. Additionally, the fourth band-pass filter 164 can pass theuplink channel of the third frequency band while attenuating otherfrequency components. Furthermore, the fifth band-pass filter 165 canpass the downlink channel of the third frequency and while attenuatingother frequency components.

Although two example multiplexer configurations are shown in FIGS. 5Aand 5B, the teachings herein are applicable to other configurations,including, for example, multiplexers including additional terminalsand/or components. Accordingly, the teachings herein are not onlyapplicable to multiplexers that multiplex two or three frequency bands,but also to other configurations, such as multiplexers that multiplexfour or more bands. Additionally, the teachings herein are alsoapplicable to multi-stage multiplexers including a plurality ofmultiplexer stages and/or configurations using multiple stages offiltering, including low-pass, high-pass and/or band-pass filtering.Furthermore, the multiplexer 150 of FIG. 5A and/or the multiplexer 170of FIG. 5B can be used in a variety of signal boosters, and are not justlimited for use in the signal boosters shown in FIGS. 3 and 4. Forexample, since the multiplexer 50 and the multiplexer 70 provideband-pass filtering, the multiplexers of FIGS. 5A and 5B can be used inconfigurations of signal boosters that do not include any band-passfilters in the signal booster's amplification paths, or inconfigurations in which only some of the signal booster's amplificationpaths include band-pass filters.

FIGS. 6A-6D illustrate various views of a signal booster 200 accordingto one embodiment. The signal booster 200 includes a housing 201, firstand second antenna ports 203 a, 203 b, top and bottom covers 207, 208, afirst printed circuit board (PCB) 211, and a second PCB 212.

FIG. 6A is a perspective view of a signal booster 200. FIG. 6B is a topplan view of the signal booster 200 of FIG. 6A with the top cover 207removed and with the first metal layer 222 a removed. FIG. 6C is abottom plan view of the signal booster 200 of FIG. 6A with the bottomcover 207 b removed and with a portion of the second metal layer 222 bremoved. FIG. 6D is a cross-section of the signal booster 200 of FIGS.6A-6C taken along the lines 6D-6D.

The housing 201 of the signal booster 200 can be used to house the firstand second PCBs 211, 212 and/or other circuitry or components of thesignal booster 200. The housing 201 can have a variety of form factors.In the illustrated configuration, the housing 201 includes a first sideportion 201 a, a second side portion 201 b, a third side portion 201 c,a fourth side portion 201 d, and a shielding or middle portion 201 e. Inthe configuration shown in FIGS. 6A-6D, the first to fourth sideportions 201 a-201 d operate as walls of the signal booster 200, and canhave a rectangular perimeter when viewed from above or below. However,other configurations are possible. As shown in FIG. 6D, the shieldingportion 201 e can extend in a plane substantially perpendicular to thefirst to fourth side portions 201 a-201 d, and can contact each of thefirst to fourth sides 201 a-201 d. The signal booster 200 can include anupper cavity 205 over the shielding portion 201 e and bounded by thefirst to fourth sides 201 a-201 d, the shielding portion 201 e, and thetop cover 207. Additionally, the signal booster 200 can include a lowercavity 206 beneath the shielding portion 201 e and bounded by the firstto fourth sides 201 a-201 d, the shielding portion 201 e, and the bottomcover 208. The housing 201 can be implemented using a variety ofmaterials, including, for example, metals, such as aluminum. It will beunderstood that the orientations are relative and the entire signalbooster 200 can be placed and held in any desired orientation.

In one embodiment, the housing 201 has a height in the range of about 1cm to about 10 cm, a width in the range of about 10 cm to about 30 cm,and a length in the range of about 10 cm to about 80 cm. Although oneexample of dimensional ranges for the housing 201 has been provided,other configurations are possible.

In the illustrated configuration, the first PCB 211 has been positionedin the upper cavity 205, and the second PCB 212 has been positioned inthe lower cavity 206. In certain configurations, the first PCB 211includes circuitry associated with one or more low frequency RF bands,such as RF bands having a frequency less than 1 GHz, and the second PCB212 includes circuitry associated with one or more high frequency RFbands, such as RF bands having a frequency greater than 1 GHz. Forexample, in one embodiment, the first PCB 211 includes circuitry forboosting at least one of Band XII, Band XIII, and Band V, and the secondPCB 212 includes circuitry for boosting at least one of Band II and BandIV. However, other configurations are possible.

In certain implementations, the first and second PCBs 211, 212 areimplemented using different materials suitable for use with thefrequency bands for which the circuitry on the PCB providesamplification. For example, in one embodiment, the first PCB 211 is usedto amplify one or more low frequency RF bands, such as Band XII, BandXIII, and/or Band V, and is implemented using FR4 board. Additionally,in certain configurations, the second PCB 212 is used to amplify one ormore high frequency RF bands, such as Band II and/or Band IV, and isimplemented using a laminate board designed for high frequency circuituse. For example, in one embodiment the second PCB 12 is a laminateincluding a ceramic filled, glass reinforced, hydrocarbon basedinsulating material, such as that used in the RO4000® commerciallyavailable from Rogers Corporation of Chandler, Ariz. Although the firstand second PCBs 211, 212 can be implemented using different materials,the teachings herein are also applicable to configurations in which thePCBs are implemented using the same materials.

Using the first and second PCBs 211, 212 rather than a single PCB canprovide a number of advantages, such as allowing the PCBs to beseparately tuned or configured for the particular bands for which thePCB provides amplification. Additionally, using two PCBs can easemanufacturing and/or reduce cost in certain configurations. Although thesignal booster 200 of FIGS. 6A-6D is illustrated for a two PCBconfiguration, the teachings herein are applicable to single PCBconfigurations or configurations using three or more PCBs.

As shown in FIG. 6D, the middle or shielding portion 201 e extendsbetween the first and second PCBs 211, 212. Configuring the signalbooster 200 in this manner can aid in providing RF shielding orisolation between circuitry on the first and second PCBs 211, 212. Forexample, when the top and bottom covers 207, 208 are attached to thehousing 201, the first and second PCBs 211, 212 can each operate in aFaraday cage or shield formed in part by the shielding portion 201 e.The shielding portion 201 e can also aid in providing thermaldissipation for the first and second PCBs 211, 212. In one embodiment,the shielding portion 201 e has a thickness in the range of about 1 mmto about 40 mm.

Although the illustrated shielding portion 201 e is implemented as apart of the housing 201, the teachings herein are applicable toconfigurations in which the shielding portion is implemented as aseparate structure.

In certain implementations, the shielding portion 201 e is implementedusing one or more heat pipes, such as the heat pipe 213 of FIG. 6D. Theheat pipe 213 can be used to improve the thermal conductivity of thehousing 201 by increasing the dissipation of heat generated by circuitryof the first and/or second PCBs 211, 212. In certain implementations,the heat pipe 213 includes one or more phase change materials. As usedherein, heat pipe refers not only to a tubular heat pipes, but also toplanar heat pipes or heat spreaders.

Furthermore, as shown in FIG. 6D, the first and second PCBs 211, 222 canbe configured to contact the shielding portion 201 e to increase heatdissipation. In certain implementations, a side of the first PCB 211contacting the shielding portion 201 e and a side of the second PCB 212contacting the shielding portion can include soldering metal to enhanceheat dissipation. Furthermore, in certain implementations, the first andsecond PCBs 211, 212 can be firmly secured against the shielding portion201 e, such as by using screws or other fasteners. Additionally, incertain configurations a thermal conductor such as thermal grease canalso be used to increase contact thus thermal conductivity, therebyhelping to further increase heat transfer from the PCBs to the housing201.

To aid in removing heat, the housing 200 can include one or more finstructures used to dissipate heat. For example, in the illustratedconfiguration, the second and fourth side portions 201 b, 201 d havebeen implemented to include heat fins 214. The heat fins 214 can be usedto dissipate heat, including, for example, heat dissipated through theshielding portion 201 e. For example, as shown in FIG. 6D, the shieldingportion 201 e extends substantially parallel to the first and secondPCBs 211, 212, which can increase thermal contact. Additionally, theshielding portion 201 e contacts the second and fourth sides 201 b, 201d, which are substantially perpendicular to the first and second PCBs211, 212 and include the heat fins 214. It has been found thatimplementing the heat dissipation structure of the signal booster 200 inthis manner can improve overall heat dissipation relative to aconfiguration in which the shielding portion 201 e is omitted and/or inwhich fins are included only on surfaces that are parallel to the PCBs,such as the top or bottom surfaces of the housing.

Certain structures associated with the first and second PCBs 211, 212have been labeled in FIGS. 6B-6D. For example, as shown in FIGS. 6B and6D, the upper cavity 205 includes a first isolation structure 221 a, afirst metal layer 222 a (e.g., a foil), first and second multiplexers225 a, 225 b, and first to fifth amplification circuits or paths231-235. Additionally, as shown in FIGS. 6C and 6D, the lower cavity 206includes a second isolation structure 221 b, a second metal layer 222 b(e.g., a foil), and sixth to ninth amplification paths 236-239.

The first to ninth amplification paths 231-239 can be used to provideboosting to different frequency channels. For example, in oneembodiment, the first PCB 211 is configured such that the firstamplification path 231 boosts a Band XII uplink channel, the secondamplification path 232 boosts a Band XIII uplink channel, the thirdamplification path 233 boosts both a Band XII downlink channel and aBand XIII downlink channel, the fourth amplification path 234 boosts aBand V uplink channel, and the fifth amplification path 235 boosts aBand V downlink channel. Additionally, in certain configurations, thesecond PCB 212 is configured such that the sixth amplification path 236boosts a Band IV downlink channel, the seventh amplification path 237boosts a Band IV uplink channel, the eighth amplification path 238boosts a Band II downlink channel, and the ninth amplification path 239boosts a Band II uplink channel. However, other configurations arepossible.

As shown in FIGS. 6B-6D, the first and second isolation structures 221a, 221 b and the first and second metal layers 222 a, 222 b can operateto provide shielding between or within the first to ninth amplificationpaths 231-239. Configuring the signal booster 200 to include the firstand second isolation structures 221 a, 221 b and the first and secondmetal layers 222 a, 222 b can improve the performance of the signalbooster 200 by, for example, reducing interference and/or feedback pathsbetween amplification stages or paths relative to a configuration inwhich the first and second isolation structures 221 a, 221 b and thefirst and second metal layers 222 a, 222 b are omitted.

The first and second isolation structures 221 a, 221 b and the first andsecond metal layers 222 a, 222 b can also provide isolation for othercomponents of the signal booster 200, including, for example, the firstand second multiplexers 225 a, 225 b of the first PCB 211 as well asmultiplexers of the second PCB 212 (not shown in FIGS. 6A-6D). Incertain implementations, first and second isolation structures 221 a,221 b and the first and second metal layers 222 a, 222 b also provideisolation for diplexers, control circuitry, and/or other components ofthe signal booster 200. In one embodiment, the first and second metallayers 222 a, 222 b include foil. In certain configurations, the firstand second isolation structures 221 a, 221 b are implemented usingmetals, such as aluminum, and can be integrated with the housing 201.

In the illustrated configuration, the first and second PCBs 211, 212have an orientation that is flipped relative to one another. Forexample, the first to fifth amplification paths 231-235 of the first PCB211 are positioned on a side of the first PCB 211 that is opposite thesecond PCB 212, and the sixth to ninth amplification paths 236-239 ofthe second PCB 212 are positioned on a side of the second PCB 212 thatis opposite the first PCB 211. Configuring the first and second PCBs211, 212 in this manner can aid in reducing RF interference between thefirst and second PCBs 211, 212 and in increasing thermal dissipation.

Additionally, configuring the first and second PCBs 211, 212 in thismanner can increase the distance between heat sources, such as PAs. Forexample, the illustrated configuration can have improved thermalperformance relative to a configuration in which PAs are positioned inclose proximity. Furthermore, in certain implementations the PAs of thefirst PCB 211 and the PAs of the second PCB 212 are positioned so thatthey are not aligned with one another with respect to the shieldingportion 201 e, which can further help in keeping the PAs relatively faraway from each other.

The first and second antenna ports 203 a, 203 b can be used to connectthe signal boosters 200 to first and second antennas (not illustrated inFIGS. 6A-6D), respectively. For example, in certain implementations, thefirst antenna port 203 a can be connected to an outdoor antenna using afirst cable, and the second antenna port 203 b can be connected to anindoor antenna using a second cable. However, other configurations arepossible, such as configurations having additional antenna ports foradditional antennas for each or different frequency bands or to supportmultiple-input multiple-output (MIMO) antennas.

Although not illustrated in FIGS. 6A-6D, the signal booster 200 caninclude a variety of other components, including, for example,fasteners, connectors, or adhesives used to assemble the signal booster200. For example, in one embodiment, the signal booster 200 can includescrews for securing the top and bottom covers 207, 208 and/or the firstand second PCBs 211, 212 to the housing 201.

Although one example of a signal booster 200 has been described, theteachings herein are applicable to other configurations of signalboosters. For example, the teachings herein are applicable toconfigurations using a single PCB, and/or to configurations using ahousing of a different form factor.

Applications

Some of the embodiments described above have provided examples inconnection with radio frequency signal boosters. However, the principlesand advantages of the embodiments can be used in other suitable systemsor apparatus.

Conclusion

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense, as opposed to anexclusive or exhaustive sense; that is to say, in the sense of“including, but not limited to.” The word “coupled”, as generally usedherein, refers to two or more elements that may be either directlyconnected, or connected by way of one or more intermediate elements.Likewise, the word “connected”, as generally used herein, refers to twoor more elements that may be either directly connected, or connected byway of one or more intermediate elements. Additionally, the words“herein,” “above,” “below,” and words of similar import, when used inthis application, shall refer to this application as a whole and not toany particular portions of this application. Where the context permits,words in the above Detailed Description using the singular or pluralnumber may also include the plural or singular number respectively. Theword “or” in reference to a list of two or more items, that word coversall of the following interpretations of the word: any of the items inthe list, all of the items in the list, and any combination of the itemsin the list.

Moreover, conditional language used herein, such as, among others,“can,” “could,” “might,” “can,” “e.g.,” “for example,” “such as” and thelike, unless specifically stated otherwise, or otherwise understoodwithin the context as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements and/or states. Thus, such conditional language is notgenerally intended to imply that features, elements and/or states are inany way required for one or more embodiments or that one or moreembodiments necessarily include logic for deciding, with or withoutauthor input or prompting, whether these features, elements and/orstates are included or are to be performed in any particular embodiment.

The above detailed description of embodiments of the invention is notintended to be exhaustive or to limit the invention to the precise formdisclosed above. While specific embodiments of, and examples for, theinvention are described above for illustrative purposes, variousequivalent modifications are possible within the scope of the invention,as those skilled in the relevant art will recognize. For example, whileprocesses or blocks are presented in a given order, alternativeembodiments may perform routines having steps, or employ systems havingblocks, in a different order, and some processes or blocks may bedeleted, moved, added, subdivided, combined, and/or modified. Each ofthese processes or blocks may be implemented in a variety of differentways. Also, while processes or blocks are at times shown as beingperformed in series, these processes or blocks may instead be performedin parallel, or may be performed at different times.

The teachings of the invention provided herein can be applied to othersystems, not only the system described above. The elements and acts ofthe various embodiments described above can be combined to providefurther embodiments.

While certain embodiments of the inventions have been described, theseembodiments have been presented by way of example only, and are notintended to limit the scope of the disclosure. Indeed, the novel methodsand systems described herein may be embodied in a variety of otherforms; furthermore, various omissions, substitutions and changes in theform of the methods and systems described herein may be made withoutdeparting from the spirit of the disclosure. The accompanying claims andtheir equivalents are intended to cover such forms or modifications aswould fall within the scope and spirit of the disclosure.

What is claimed is:
 1. A radio frequency signal booster comprising: afirst antenna port; a second antenna port; a first diplexer including anantenna terminal, a first terminal, and a second terminal, wherein theantenna terminal is electrically connected to the first antenna port; asecond diplexer including an antenna terminal, a first terminal, and asecond terminal, wherein the antenna terminal of the second diplexer iselectrically connected to the second antenna port; a Band XII uplinkamplification circuit including an input electrically connected to thesecond antenna port by way of the first terminal of the second diplexer,and an output electrically connected to the first antenna port by way ofthe first terminal of the first diplexer, wherein the Band XII uplinkamplification circuit is configured to provide amplification to a BandXII uplink channel; a Band XIII uplink amplification circuit includingan input electrically connected to the second antenna port by way of thefirst terminal of the second diplexer and an output electricallyconnected to the first antenna port by way of the first terminal of thefirst diplexer, wherein the Band XIII uplink amplification circuit isconfigured to provide amplification to a Band XIII uplink channel; and ashared downlink amplification circuit including an input electricallyconnected to the first antenna port by way of the first terminal of thefirst diplexer, and an output electrically connected to the secondantenna port by way of the first terminal of the second diplexer,wherein the shared downlink amplification circuit is configured toprovide amplification to a Band XII downlink channel and to provideamplification to a Band XIII downlink channel, wherein the shareddownlink amplification circuit comprises at least one amplifierconfigured to simultaneously boost both the Band XII downlink channeland the Band XIII downlink channel, and at least one bandpass filterconfigured to pass both the Band XII downlink channel and the Band XIIIdownlink channel.
 2. The radio frequency signal booster of claim 1,further comprising: a first multiplexer including an antenna terminalelectrically connected to the first terminal of the first diplexer,wherein the output of the Band XII uplink amplification circuit iselectrically connected to the first antenna port by way of a firstterminal of the first multiplexer and by way of the first terminal ofthe first diplexer, wherein the output of the Band XIII uplinkamplification circuit is electrically connected to the first antennaport by way of a second terminal of the first multiplexer and by way ofthe first terminal of the first diplexer, wherein the input of theshared downlink amplification circuit is electrically connected to thefirst antenna port by way of a third terminal of the first multiplexerand by way of the first terminal of the first diplexer; and a secondmultiplexer including an antenna terminal electrically connected to thefirst terminal of the second diplexer, wherein the input of the Band XIIuplink amplification circuit is electrically connected to the secondantenna port by way of a first terminal of the second multiplexer and byway of the first terminal of the second diplexer, wherein the input ofthe Band XIII uplink amplification circuit is electrically connected tothe second antenna port by way of a second terminal of the secondmultiplexer and by way of the first terminal of the second diplexer,wherein the output of the shared downlink amplification circuit iselectrically connected to the second antenna port by way of a thirdterminal of the second multiplexer and by way of the first terminal ofthe second diplexer.
 3. The radio frequency signal booster of claim 2,further comprising: a Band V uplink amplification circuit configured toprovide amplification to a Band V uplink channel, wherein an output ofthe Band V uplink amplification circuit is electrically connected to thefirst antenna port by way of a fourth terminal of the first multiplexerand by way of the first terminal of the first diplexer, wherein an inputof the Band V uplink amplification circuit is electrically connected tothe second antenna port by way of a fourth terminal of the secondmultiplexer and by way of the first terminal of the second diplexer; anda Band V downlink amplification circuit configured to provideamplification to a Band V downlink channel, wherein an input of the BandV downlink amplification circuit is electrically connected to the firstantenna port by way of a fifth terminal of the first multiplexer and byway of the first terminal of the first diplexer, wherein an output ofthe Band V downlink amplification circuit is electrically connected tothe second antenna port by way of a fifth terminal of the secondmultiplexer and by way of the first terminal of the second diplexer. 4.The radio frequency signal booster of claim 3, further comprising: athird multiplexer including an antenna terminal electrically connectedto the second terminal of the first diplexer; and a fourth multiplexerincluding an antenna terminal electrically connected to the secondterminal of the second diplexer.
 5. The radio frequency signal boosterof claim 4, further comprising: a Band IV downlink amplification circuitconfigured to provide amplification to a Band IV downlink channel,wherein an input of the Band IV downlink amplification circuit iselectrically connected to the first antenna port by way of a firstterminal of the third multiplexer and by way of the second terminal ofthe first diplexer, wherein an output of the Band IV downlinkamplification circuit is electrically connected to the second antennaport by way of a first terminal of the fourth multiplexer and by way ofthe second terminal of the second diplexer; and a Band IV uplinkamplification circuit configured to provide amplification to a Band IVuplink channel, wherein an output of the Band IV uplink amplificationcircuit is electrically connected to the first antenna port by way of asecond terminal of the third multiplexer and by way of the secondterminal of the first diplexer, wherein an input of the Band IV uplinkamplification circuit is electrically connected to the second antennaport by way of a second terminal of the fourth multiplexer and by way ofthe second terminal of the second diplexer.
 6. The radio frequencysignal booster of claim 5, wherein the first multiplexer is implementedwith a first plurality of multiplexer stages, and wherein the secondmultiplexer is implemented with a second plurality of multiplexerstages.
 7. The radio frequency signal booster of claim 5, furthercomprising: a Band II downlink amplification circuit configured toprovide amplification to a Band II downlink channel, wherein an input ofthe Band II downlink amplification circuit is electrically connected tothe first antenna port by way of a third terminal of the thirdmultiplexer and by way of the second terminal of the first diplexer,wherein an output of the Band II downlink amplification circuit iselectrically connected to the second antenna port by way of a thirdterminal of the fourth multiplexer and by way of the second terminal ofthe second diplexer; and a Band II uplink amplification circuitconfigured to provide amplification to a Band II uplink channel, whereinan output of the Band II uplink amplification circuit is electricallyconnected to the first antenna port by way of a fourth terminal of thethird multiplexer and by way of the second terminal of the firstdiplexer, wherein an input of the Band II uplink amplification circuitis electrically connected to the second antenna port by way of a fourthterminal of the fourth multiplexer and by way of the second terminal ofthe second diplexer.
 8. The radio frequency signal booster of claim 7,wherein the Band XII uplink channel has a frequency range of about 698MHz to about 716 MHz, wherein the Band XII downlink channel has afrequency range of about 728 MHz to about 746 MHz, wherein the Band XIIIuplink channel has a frequency range of about 776 MHz to about 787 MHz,wherein the Band XIII downlink channel has a frequency range of about746 MHz to about 757 MHz, wherein the Band V uplink channel has afrequency range of about 824 MHz to about 849 MHz, wherein the Band Vdownlink channel has a frequency range of about 869 MHz to about 894MHz, wherein the Band IV uplink channel has a frequency range of about1710 MHz to about 1755 MHz, wherein the Band IV downlink channel has afrequency range of about 2110 MHz to about 2155 MHz, wherein the Band IIuplink channel has a frequency range of about 1850 MHz to about 1910MHz, wherein the Band II downlink channel has a frequency range of about1930 MHz to about 1990 MHz.
 9. The radio frequency signal booster ofclaim 2, wherein the first multiplexer and the second multiplexer areconfigured to multiplex a first plurality of radio frequency bands eachhaving a frequency less than 1 GHz, wherein the radio frequency signalbooster further comprises a third multiplexer and a fourth multiplexerconfigured to multiplex a second plurality of radio frequency bands eachhaving a frequency greater than 1 GHz.
 10. The radio frequency signalbooster of claim 2, wherein the first multiplexer comprises a combinerelectrically connected to the antenna terminal of the first multiplexer,a first bandpass filter electrically connected between the combiner andthe first terminal of the first multiplexer, a second bandpass filterelectrically connected between the combiner and the second terminal ofthe first multiplexer, and a third bandpass filter electricallyconnected between the combiner and the third terminal of the firstmultiplexer.
 11. The radio frequency signal booster of claim 1, furthercomprising a housing that houses the first diplexer, the seconddiplexer, the Band XII uplink amplification circuit, the Band XIIIuplink amplification circuit, and the shared downlink amplificationcircuit.
 12. The radio frequency signal booster of claim 11, wherein thehousing has a height in the range of about 1 cm to about 10 cm, a widthin the range of about 10 cm to about 30 cm, and a length in the range ofabout 10 cm to about 80 cm.
 13. The radio frequency signal booster ofclaim 11, wherein the housing is implemented in metal.
 14. The radiofrequency signal booster of claim 11, wherein the housing includes oneor more heat fins configured to dissipate heat.
 15. The radio frequencysignal booster of claim 11, further comprising: a first antennaconfigured to wirelessly communicate with one or more base stations of acellular network; a first cable configured to connect between the firstantenna and the first antenna port; a second antenna configured towirelessly communicate with one or more mobile devices of the cellularnetwork; and a second cable configured to connect between the secondantenna and the second antenna port.
 16. The radio frequency signalbooster of claim 11, further comprising a circuit board within thehousing, wherein the Band XII uplink amplification circuit, the BandXIII uplink amplification circuit, and the shared downlink amplificationcircuit are implemented on the circuit board.
 17. The radio frequencysignal booster of claim 11, further comprising an isolation structureconfigured to provide shielding between the Band XII uplinkamplification circuit, the Band XIII uplink amplification circuit, andthe shared downlink amplification circuit.
 18. The radio frequencysignal booster of claim 1, further comprising a control circuitconfigured to control an output power level of the Band XII uplinkamplification circuit, an output power level of the Band XIII uplinkamplification circuit, and an output power level of the shared downlinkamplification circuit.
 19. The radio frequency signal booster of claim18, wherein the control circuit is further configured to provideautomatic gain control, automatic oscillation detection, and automaticshutdown.
 20. The radio frequency signal booster of claim 18, whereinthe control circuit includes one or more embedded CPUs.
 21. The radiofrequency signal booster of claim 1, wherein the at least one band-passfilter passes a frequency range of about 728 MHz to about 757 MHz, andwherein the at least one band-pass filter provides attenuation to afrequency range of about 698 MHz to about 716 MHz and to a frequencyrange of about 776 MHz to about 787 MHz.
 22. The radio frequency signalbooster of claim 1, wherein the shared downlink amplification circuitfurther comprises one or more digital attenuators.
 23. The radiofrequency signal booster of claim 1, wherein the shared downlinkamplification circuit further comprises one or more analog attenuators.24. The radio frequency signal booster of claim 1, wherein the at leastone bandpass filter comprises one or more surface acoustic wave (SAW)filters.
 25. The radio frequency signal booster of claim 1, wherein theat least one bandpass filter comprises one or more ceramic filters. 26.The radio frequency signal booster of claim 1, wherein the at least oneamplifier comprises one or more power amplifiers.
 27. The radiofrequency signal booster of claim 1, wherein the at least one amplifiercomprises one or more low noise amplifiers.
 28. The radio frequencysignal booster of claim 1, implemented to boost network signal strengthfor a plurality of mobile devices operating with different wirelesscarriers.
 29. The radio frequency signal booster of claim 1, wherein theBand XII downlink channel and the Band XIII downlink channel areseparated in frequency by less than about 10 MHz.
 30. The radiofrequency signal booster of claim 29, wherein the Band XII downlinkchannel and the Band XIII downlink channel are abutting.